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6th International Conference on Communications, Signal Processing, and Systems (ICCSPS)

作者： Guo, Pengcheng Ren, Bingyin Zhang, Yongxin Luoyang Elect Equipment Test Ctr China Luoyang 471001 Peoples R China

ISBN: (纸本)9789811065712;9789811065705

In this paper, a Generalized Space Shift Keying modulation scheme combined with convolutional coding is proposed, and the convolutional coding structure is given. Firstly, the transmission model and the convolutional coding structure of the system are introduced. Secondly, the decoding algorithm of antenna detection used in the receiver is analyzed, and the complexity of the receiving algorithm is compared. Finally, the transmission performance of the scheme is simulated and analyzed in the Rician fading channel, and the advantages and disadvantages of the scheme, traditional Space Shift Keying modulation and Generalized Space Shift Keying modulation are compared. The results show that the proposed scheme can prove the anti-channel fading performance of the system.

关键词： convolutional coding Rician fading channel Generalized Space Shift Keying

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The impact of convolutional coding on the uplink performance of UMTS air interface

The impact of convolutional coding on the uplink performance...

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6th International Conference on Telecommunication in Modern Cable, Satellite and Broadcasting Services

作者： Moradi, H Ahmadian, M Iran Telecommun Res Ctr Tehran Iran

ISBN: (纸本)0780379632

Third generation of mobile communications systems (3G) integrate a wide variety of wireless services as multimedia services. Universal Mobile Telecommunications System (UMTS) is the main standard of 3G with WCDMA air interface. The WCDMA provides both error detection and error correction as channel coding scheme. The first one is provided by Cyclic Redundancy Check (CRC) coding and the latter by a combination convolutional code with turbo decoding. For convolutional coding, both rate 1/2 and 1/3 are considered. This paper gives simulation observations of rate 1/3 convolutional coding effect on reverse link (uplink) for voice service and compares results with an uncoded system with a description of WCDMA technology and its channel coding scheme. A Rake combiner is implemented in receiver to compensate undesired channel effect and a Viterbi soft decision decoder performs decoding. FDD mode of WCDMA is selected as the operation mode of transmission. Conclusions are shown in Bit Error Rate (BER) curves and no CRC coding or interleaving is used.

关键词： channel coding convolutional coding error correction WCDMA viterbi decoder and spreading

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Performance Analysis in SIR-Based Power Controlled Uplink DS-CDMA Systems using Soft Handover technique with convolutional coding Scheme

Performance Analysis in SIR-Based Power Controlled Uplink DS...

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4th International Conference on Wireless Communications, Networking and Mobile Computing

作者： Mobini, Z. Mohammadi, M. A. Rohi, H. A. Ardebilipour, M. KN Toosi Univ Technol KNTU Tehran Iran

ISBN: (纸本)9781424421077

The coordination of power control and soft handover has a major effect on DS-CDMA systems. In this paper, we investigate the power controlled DS-CDMA reverse-link performance under soft handover with convolutional coding scheme. It is shown that system under soft handover has less sensitivity against incrementing the number of users. The effect of the link balance is evaluated through simulation by considering the reverse-link behavior with power control and soft handover. It observed that the differential loss between two links under soft handover decreases the uplink performance. Finally it is pointed out that by using convolutional error correction coding scheme an additional gain is obtained

关键词： Direct Sequence Code Division Multiple Access (DSCDMA) convolutional coding Power Control Rake Receiver Soft Handover (SHO)

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Research on a TCM-based Transmission Approach for EM-MWD by Combining Phase Modulation and convolutional coding

Research on a TCM-based Transmission Approach for EM-MWD by ...

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IEEE International Instrumentation and Measurement Technology Conference (I2MTC)

作者： Zhang, Cheng Dong, Haobin Ge, Jian Liu, Huan Wang, Jiahao Luo, Wang Yuan, Zhiwen Zhu, Jun Zhang, Haiyang China Univ Geosci Sch Automat Wuhan 430074 Hubei Peoples R China Hubei Key Lab Adv Control & Intelligent Automat Wuhan 430074 Hubei Peoples R China Sci & Technol Near Surface Detect Lab Wuxi 214035 Jiangsu Peoples R China China Univ Geosci Sch Mech Engn & Elect Informat Wuhan 430074 Hubei Peoples R China

ISBN: (纸本)9781538634608

In practical applications of electromagnetic measurement while drilling (EM-MWD) in the underground coal mine, the signal-to-noise ratio (SNR) of the receiver cannot always meet the requirements of reliable communication conditions due to the earth-attenuation, interfering signal from a well site, etc. Traditional digital communication systems use independent design coding and modulation techniques to improve system performance. The coding is mainly achieved by introducing redundant bits and the improvement of error performance is at the expense of information rate. Aimed to solve this problem, we use a coding technique based on trellis coded modulation (TCM) to maximize the minimum distance between modulated output sequences and achieve significant coding gain. Simulation and experiments show that the system can improve the anti noise performance of the system by obtaining a coding gain without reducing the transmission rate. Compared to the uncoded quadrature phase shift keying (QPSK), TCM can achieve a coding gain of at least 3 dB under the same transmitting rate. At that time, as the number of TCM system states or trace back depth increases, the coding gain is further enhanced. The TCM code modulation method can be used in an EM-MWD system to improve the system performance.

关键词： EM-MWD convolutional coding coding gain Trellis coded modulation

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Performance of unequalized frequency-hopped TDMA with convolutional coding on dispersive fading channels

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International Journal of Wireless Information Networks 1994年第2期1卷 107-115页

作者： Ariyavisitakul, Sirikiat Chang, Li Fung Radio Research Department Bellcore Red Bank 07701-7040 New Jersey 331 Newman Springs Rd. United States

Increasing demand for wireless personal communications has stimulated research on new digital radio technologies that are optimized for various service applications and environments. This paper discusses the performance of a slow-frequency-hopped time-division multiple-access (SFH-TDMA) technique, which has been proposed as a "high-tier" extension of a low-complexity TDMA architecture optimized for low-power pedestrian applications. The SFH-TDMA technique considered uses QPSK modulation and rate-1/2 convolutional coding. Numerical results for a wide range of fading rates are obtained through analytical calculation of the effective signal-to-noise ratio combined with a simulation approach which incorporates measured multipath channels and actual frequency correlation among contiguous hopping channels. The results indicate that the SFH-TDMA technique can tolerate root-mean-square (rms) delay spread up to several bit periods without a need for adaptive equalization, but also point to the need for fast power control when the fading is slow and the rms delay spread is much smaller than the bit period. This work is targeted toward understanding the implications to local exchange networks of wireless technology alternatives that could provide access to those networks. © 1994 Plenum Publishing Corporation.

关键词： convolutional coding fading channels Frequency hopping TDMA

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PERFORMANCE OF convolutional coding WITH SYMBOL ERASURE FOR QPSK FREQUENCY-SELECTIVE FADING CHANNELS

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IEICE TRANSACTIONS ON COMMUNICATIONS 1993年第2期E76B卷 139-147页

作者： ZHOU, H DENG, RH NATL UNIV SINGAPORE DEPT ELECT ENGN SINGAPORE 0511 SINGAPORE NATL UNIV SINGAPORE DEPT ELECT & COMP ENGN SINGAPORE 0511 SINGAPORE

In this paper, we study the performance of convolutional coding using an error-and-erasure correction Viterbi decoder for pi/4-shift QDPSK mobile radio transmission. The receiver uses received signal envelope as channel state information to erase unreliable symbols instead of making explicit decision before decoding. The performance study is carried out over frequency-selective fading channel with additive white Gaussian noise, co-channel interference and propagation delay spread. The results show that decoding with symbol erasure can significantly improve the system transmission performance compared to decoding without symbol erasure.

关键词： FREQUENCY-SELECTIVE FADING convolutional coding ERROR-AND-ERASURE CORRECTION VITERBI DEcoding

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Distributed Estimation With convolutional coding in Wireless Sensor Networks

Distributed Estimation With Convolutional Coding in Wireless...

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International Conference on Automatic Control and Artificial Intelligence

作者： L. Wu Y. Liu Department of Computer Science Guangdong University of Education College of Automation Science and Engineering South China University of Technology

ISBN: (纸本)9781627481205

The problem of distributed estimation of an unknown noise-corrupted parameter in wireless sensor networks (WSNs) is considered in this paper. Because of the impact of noise channels, convolutional coding is used to protect the transmission of sensor observations here. To minimize the total power consumption, a novel kinds of power scheduling is derived. The formulas of the proposed power scheduling suggest local sensors with poor observation qualities should decrease their quantization levels and the levels should be also related to coding methods, channel qualities, given mean squared error (MSE) and local signal-to-noise ratio (SNR). Finally, simulation results show that not only is the scheme energy-efficient but also it achieves comparable performance of a given MSE.

关键词： Wireless sensor networks Distributed estimation convolutional coding

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Superposition Modulation with Irregular convolutional coding

Superposition Modulation with Irregular Convolutional Coding

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IEEE Global Communications Conference

作者： Meelis Noemm Alaa Mourad Peter Adam Hoeher Faculty of Engineering University of Kiel

ISBN: (纸本)9781467309202

Bijective mapping techniques with uniformly distributed constellation diagrams, like PSK and QAM, are standard in today's communications systems. Yet, it is well known that without additional effort in form of active signal shaping, bijective mapping techniques are not capacity achieving. In recent years, an alternative technique called superposition modulation (SM) has been investigated, which theoretically capacity is achieving on the Gaussian channel. However, non-bijective mapping (which can be interpreted as lossy source coding) is challenging with respect to the design of proper channel codes. In this paper, the suitability of irregular convolutional coding in conjunction with superposition modulation is investigated. With proper code design, this combination is capable of achieving 6 bits/symbol at just 0.7 dB away from the Shannon capacity limit given a memory-4 mother code.

关键词： convolutional coding lossy source coding Quadrature amplitude modulation PS-K Phase shift keying Bijective Constellation diagram MAPPING(MATHEMATICAL)

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Novel Scheme of Orthogonal convolutional coding and Non-iterative Decoding for Mobile Satellite Communication Systems

Novel Scheme of Orthogonal Convolutional Coding and Non-iter...

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IEEE Vehicular Technology Conference

作者： Xiangming Meng Sheng Wu Linling Kuang Zuyao Ni Jianhua Lu Department of Electronic Engineering Tsinghua University Beijing China Tsinghua Space Center Tsinghua University Beijing China

ISBN: (纸本)9781479980925

Iterative decoding of orthogonal convolutional code is widely used for its excellent performance. However, the iterations lead to high complexity and long decoding delay, which is unsuitable for low-rate voice service in mobile satellite communications with on-board processing. In this paper, a novel scheme of orthogonal convolutional coding as well as an associated non-iterative joint decoding algorithm based on factor graph are proposed. Due to its non-iterative nature, this novel scheme has low decoding complexity and short latency, which indicates its potential on-board use in the low-rate satellite voice service, or other kinds of services with a high bit error rate (BER) tolerance and a tight delay requirement. Simulation results demonstrate the efficacy of the proposed novel coding scheme and non-iterative decoding algorithm in both AWGN and Rician channels.

关键词： Orthogonal convolutional code mobile satellite communication joint decoding factor graph mobile satellite communication Factor Graph Satellite communication systems convolutional coding DEcoding voice service Orthogonal Iterative decoding

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Gaussian Image Denoiser Based on Deep convolutional Sparse coding with Attention Mechanism

Gaussian Image Denoiser Based on Deep Convolutional Sparse C...

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IEEE International Conference on Green Computing and Communications

作者： Yu Shi Yige Xu Zhenya Wang Yingying Hua Haoran Gao Benchang Zheng Be Honors Schoo Nnjing Universiy of Poss nd TeecounicionsBe Honors Schoo Nnjing Universiy of Poss nd TeecounicionsChin Acdey of Lunch Vehice TechnoogyCoege of Teecounicion nd Inforion Engineering Nnjing Universiy of Poss nd TeecounicionsSchoo of Inforion Engineering Wuhn Universiy of TechnoogyChin Acdey of Lunch Vehice Technoogy

ISBN: (数字)9781728176475

ISBN: (纸本)9781728176482

Image denoising is the foundation of computer vision and a classic research project of computer vision. Currently, image denoising is widely used in various fields. In order to perform image denoising more effectively, we propose a deep convolutional sparse coding based on the attention mechanism (DCSCA) denoising model. In order to identify noise and remove noise more effectively, we sparsely encode the feature map instead of encoding the original image. Our model introduces attention blocks in the network structure, which allows our model to mine the noise hidden behind complex images. Our model has the advantages of a compact network structure and does not involve complex optimization models. We did not use the traditional mean square error (MSE) as our loss function, and chose to combine the loss function L1 with ssim. Compared with the most advanced methods, our model can produce better denoising results than some of the latest methods.

关键词： Noise reduction Convolution Image denoising Computational modeling convolutional codes Image coding Task analysis image denoising Noise reduction task analysis convolutional coding image coding Computational modeling images Convolution NETWORK STRUCTURE Mean square error computer vision Sparse coding feature map

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